"This next song that I'm about to play you is brand new".
Lorde will play Coachella on Sunday with an encore performance on April. 23.
"It's a record about all the ups and downs of being twenty-something, and specifically all of the ups and downs of an evening", she said in the Californian desert.
Lorde has appeared for her first live show in two and a half years as a warm up for her appearance at Coachella this weekend.
"Homemade Dynamite" resides "in that first category where everything is good", Lorde added.
The new song is from her forthcoming album, Melodrama, due out on June 16. Her setlist also included a number of familiar favorites, such as "Royals", "Tennis Court", "Team" and her Disclosure collaboration "Magnets".
And it means Lorde has officially continued her streak of speaking directly to the secrets in my heart that I wish were known and seen.
In what Billboard described as a "far cry from her stripped down performance" in 2014, Lorde's full-production set was full of lights, dancing and even a box full of dancers replicating a club scene.